Container filling machine



Aprfl 16, 1968 E. s. MINARD CONTAINER FILLING MACHINE Filed Oct. 13, 1965 5 Sheets-Sheet l INVENTOR. EVERETT S. MINARD ATTORNEY April 16; 1968' E. s. MINARD CONTAINER FILLING MACHINE 5 Sheets-Sheet 3 Filed Oct. 13, 1965 INVENTOR EVERETT S. MINARD ATTORNEY Apri? 16, 1968 E. s. MINARD CONTAINER FILLING MACHINE 5 Sheets-Sheet 5 Filed Oct. 15, 1965 INVENTOR EVERETT s. MINARD ATTORNEY QN wm m mm \h Mm United States Patent AESTRALT UP THE DEJLUSURE A control apparatus having cam tracks and pairs of rollers in engagement therewith, said track and rollers being positioned to minimize the clearance between the tracks and rollers for accurately positioning movable members to which the pairs of rollers are attached.

This invention relates to a container filling machine and in particular to a container filling machine by which liquid is metered by a meterin mechanism having a cylinder and a piston slidable in the cylinder. In filling machines by which liquid is metered into containers by such a metering mechanism, it is known to have the piston follow a cam on the intake and discharge strokes of the piston; the cam being engaged by a roller mounted to each piston. The cam arrangement usually includes an upper cam track having a cam surface and a lower cam track having a cam surface. The upper cam track is usually orn'tted in the region or" the cam which serves to drive the rollers upwardly, hence in this region the rollers can engage only the cam surface of the lower cam track. The lower cam track extends the full distance of travel of the rollers.

When the rollers contact both (he can: surfaces of the upper and lower cam tracks, each cam surface tends to impart opposite forces to each of the rollers. The cam surface of the upper cam track tends to rotate the rollers in one direction, while the cam surface of the lower earn track tends to rotate the rollers in the opposite direction. In order to obtain metering and filling accuracy the upper and lower cam tracks should be so ssaced as to minimize clearance between the upper and lower cam tracks and the rollers. When such clearance is minimal, wear on the rollers is maximal. When the rollers become worn, they may ce e to roll on the cam because of flat spots, and further v. of the rollers talzes place becathey slide in engagement with the cam track-s. Metering and filling accuracy is reduced when the rollers become worn.

In an embodiment of the invention, two rollers are mount-ed for independent rotation by the piston of a container filling machine, one of the rollers being engageahle with the upper earn tracl: but not with the lower cam track and the other roller heing engageable with the lower cam track but not with the upper cam track. Each roller engages only its respective cam track and rotates in only one direction, thus reducing wear.

In the drawings:

FIGURE 1 is a schematic, developed view of a cam of a known container filling machine;

FIGURE 2 is a side view showing fragmentary portions of the end of the intake stroke portion and the beginning of the discharge stroke portion of the upper and lower cam tracks of a cam and a reservoir, together with metering mechanisms;

FIGURE 3 is a side view similar to FIGURE 2, but showing the end of the discharge portion of the upper and lower earn tracks of the cam;

FIGURE 4 is sectional view showing a pair of rollers mounted for independent rotation on a pin connected to a piston of the metering mechanism, and upper and lower cam track's engaged with the rollers;

FlGURE 5 is a side View showing structure like that shown in FIGURES 2, 3 and 4, but showing the lower cam track, instead of the upper cam track, spring loaded; and

FIGURE 6 is a sectional View of the structure shown in FIGURE 5, showing a pair of rollers mounted for independent rotation on a pin connected to a piston of the metering mechanism and upper and lower cam tracks engaged with the rollers.

Rercrring now to FIGURE 1 of the drawings, there is shown a known cam arrangement 1! having an upper cam track 11 and a lower cam track 12. Rollers 13 mounted on pistons (not shown) slidable in respective cylinders 1 tof each metering mechanism generally indicated at 15, engage the cam arrangement ltl. Starting from the left end of FIGURE 1 and proceeding to the right, the rollers 13 engage ascending intake portion 12' of the lower cam track 12; as the metorins mechanisms 15 and their rollers 13 move relative to the cam 10, the rollers 13 successively reach the high point id of the lower cam track 12, and thereafter the rollers 13 roll between the descending discharge portion 12" of the lower cam track 12 and the descending cam track Ill. Examples of known filling machines in which cams such as the cam Iltl shown in FIGURE 1 are disclosed, and in which the pro-sent invention is employable, are United States Patent No. 2,666,564, and Unite-d States Patent No. 2,896,676 in its FlGURiES 1 through 21) and in its related written description.

Roerring now to the embodiment of the invention shown in FIGURES 2, 3 and 4 of the drawings, there are shown spaced apart metering mechanisms generally indicate-d at 20, each of which includes a piston 21 and a cylinder 22. Each piston 21 driven by its respective rollers is slidable in its respective cylinder 22 and adapted to draw liquid from a reservoir 2-3 through an inlet port 24, through a valve port housing 3.5 and into the cylinder 22 of the intake stroke of the piston 21. The piston 21 can force liquid under pressure from the cylinder 22, out oi the valve port housing 25, and through an outlet port 26, when the valve 27 is in the position shown in FIG- URE 4. When the valve 27 is in its lower position, liquid communication exists between the reservoir 23, the inlet port 24, the valve port housing and. the cylinder 22.

As each of the metering mechanisms 2t} is identical, -e reference characters designate like components of each. A pin 28 is secured to the piston 21 by means of its threaded portion The pin 28 mounts spaced apart rollers and 3E which may he composed of any suitable material such as steel or a suitable plastic material such as polytetrsliuomethylene, sold commercially under the name 'i fion.

A guide block is disposed between the side of the piston 22. and the roller 31 and can move in a slot 33 in the cylinder 22. A shoulder 34 of the pin. 28 serves to hold the guide block 32 against the piston 21. A washer 35' received by the pin 28, is positioned between the rollers 34) and 31. A hex-shaped head can be used to turn the pin 23 and serves to prevent the rollers and 31 and the washer irorn sliding oil the pin 28.

A cam generally indicated at 37 has an. upper cam track 33 having a lower cam surface 38 and a lower cam track 39 having an upper earn track 39. The rollers 3t can engage the upper track 33, but not the lower cam track 39, and the rollers 31 can engage the lower cam track 39 but not the earn track 38. The cam tracks 3% and 39 are shown to be orlset relative to each other. 'The rollers 36 in contact with upper cam traclc 38 always rotate in one direction, and the rollers Ell in contact with the lower cam track 39 always rotate in the opposite direction.

FIGURE 2 shows an ascending intake portion iii of the cam track 39 which is joined to a descending discharge portion 37 at a high point 42. The upper cam track 38 is shown to have movable sections 3311 and 38c and a stationary section 3312. The section 33a can engage not more than two rollers 39 at a time at the beginning of the discharge stroke portion of the piston cycles, the section 380 cam engages not more than two rollers 39 at a time at the end of the discharge stroke portion of the piston cycles, and the section 38b engages the rollers 34 between the sections 38a and 38c. The sections 38a and 38c are spring urged against the rollers 30 by biasing mechanisms 43 while the section 3811 of the upper cam track 33 is rigidly secured to the lower cam track 39 by brackets 44. Brackets 45 and their biasing mechanisms 45 secure the movable sections 38a and 330 to the lower cam track 39. Each bracket 45 has an upstanding guide bore 46 which receives a guide rod 46. A threaded upper portion 47 of the guide rod 46 receives nuts 48 and 49. The nut 43 is threaded against the nut 49 to lock the nut 49 in place. The nut 49 is spaced a small distance from the upper stop surface 50 of the bracket 45. Threaded lower portion 51 of each guide rod 46 is threadably received by each respective movable section 33a and 38c. A spring 52 encircling each guide rod 46' abuts at one end against the respective cam section 38a and 380 and at its other end agai st the fac 53 of the respective bracket 45.

The embodiment of FIGURES and 6 is the some as the embodiment of FIGURES 2, 3 and 4, except that the lower cam track 39 rather than the upper section 33, is spring loaded. Hence, the same reference characters re used except where the structural components are reversed.

In the embodiment of FIGURES 5 and 6 the lower cam track 3% has movable sections 39:: and 39c and a stationary section 3%. Brackets 54 are secured to the continuous upper cam track 38 and the lower cam track 3). The sections 390 and 39c are urged upwardly into engagement with rollers 31 as seen in FIGURES 5 and 6 by biasing mechanisms generally indicated at 57.

In the operation of the machine in accordance with FIGURES 2, 3 and 4 of the drawings, the cam 37 being stationary and the metering mechanisms and their rollers and 31 moving in a circular pattern, the rollers 30 successively engage the sections 38a, 38b and 380 of the upper cam track 38 and the rollers 31 continuously engage the cam track 39. The rollers 30 will always rotate in one direction, whereas the rollers 31 will always rotate in the opposite direction. As the rollers 30 and 31 are guided by the cam tracks 38 and 39, the pistons 21 move on their intake and discharge strokes in synchronism with their respective valves 27 as is conventional so that containers (not shown) are successively filled by the liquid passing through respective outlet ports 26. The biasing mechanisms will urge the movable sections 38a and 380 against the rollers 30, and the rollers 31 will thus be urged against the cam 39. The weight of the pistons 21 will also aid in urging the rollers 31 against the cam track 39.

The operation of the embodiment of FIGURES 5 and 6 is the same as the operation of the embodiment of FIG- URES 2, 3 and 4 except that the biasing mechanisms 57 urge the movable sections 56a and 560 against no more than two rollers 31 which in turn insure engagement of the rollers 30 with the cam 38.

Although the metering mechanisms 15 are illustrated as being disposed vertically in a circular arrangement, these metering mechanisms can be disposed horizontally in a radial arrangement.

The rollers 30 and 31 need not be mounted on a single pin 28, as illustrated. These rollers can be mounted separately one above the other, or they can be mounted on opposite sides of the piston.

Other embodiments and modifications of this invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within the scope as best defined by the appended claims.

What is claimed is:

1. A filling machine, comprising: cam means having horizontally and vertically offset, parallel first and second cam surfaces, at least one metering mechanism including a cylinder and a piston movable relative to said cam surfaces for metering liquid into said cylinder on its intake stroke and for discharging liquid on its discharge stroke, a pin secured to said piston, and first and second rollers received by said pin for independent rotation, said first and second cam surfaces being positioned relative to said first and second rollers so that said first roller engages only said first cam surface and second roller engages only said second cam surface and said first and second cam surfaces being spaced for simultaneously engaging their respective rollers to restrict movement of the piston relative to the cam surfaces as said metering mechanism moves along said cam means.

2. A filling machine, comprising: a cam having spaced apart first and second cam' tracks, said first and second carn tracks having respective first and second cam surfaces, said cam surfaces being parallel and horizontally and vertically offset, at least one metering mechanism including a cylinder and a piston movable relative to said cam surfaces for metering liquid into said cylinder on its intake stroke and for discharging liquid on its discharge stroke, first and second rollers, a single axis pin mounting said first and second rollers to said piston to effect engagement of said first roller only With said first cam surface to effect engagement of said second roller only with said second cam surface, said first and second cam surfaces bemg spaced to minimize clearance between the rollers and the cam surfaces which they engage as said metering mechanism moves along said cam track, one of said cam tracks having a movable section, and means for urging the cam surface of said movable section into contact with its related roller so that the other roller is urged into contact with the cam surface of the other cam track.

3. A filling machine, comprising: a reservoir adapted to contain liquid, metering mechanisms to receive liquid from said reservoir, each metering mechanism including a cylinder and a piston for metering liquid into said cylinder during travel on its intake stroke and for discharging liquid from said cylinder during travel on its discharge stroke, cam means for sequentially actuating said pistons on the intake and discharge strokes, said reservoir and metering mechanism being rotatable as a unit relative to said cam means, said cam means having horizontally and vertically offset, parallel upper and lower cam surfaces, pairs of first and second rollers, and a single axis pin mounting each pair of said first and second rollers to each piston to effect rolling engagement of said first rollers only with said upper cam surface and to effect rolling engagement of said second rollers only with said lower cam surface, said first and second rollers of each pair being spaced to minimize clearance between the rollers and the cam surfaces which they engage as the pairs of rollers ro-ll along the cam surfaces and said reservoir and metering mechanisms rotate as a unit.

4. A filling machine, comprising: a reservoir adapted to contain liquid, metering mechanisms to receive liquid from said reservoir, each metering mechanism including a cylinder and a piston for metering liquid into said cylinder during travel on its intake stroke and for discharging liquid from said cylinder during travel on its discharge stroke, cam means for sequentially actuating said pistons on their intake and discharge strokes, said reservoir and metering mechanisms being rotatable as a unit relative to said cam means, said cam means including parallel spaced apart first and second cam tracks having respective first and second surfaces, said first and second surfaces being horizontally and vertically offset, a pair of first and second rollers for each piston, a single axis pin mounting one pair of said first and second rollers to each piston to effect engagement of said first rollers only with said first cam surface and to effect engagement of said second rollers only with said second cam surface as said reservoir and metering mechanisms rotate as a unit along said cam' means, one of said first and second cam tracks having at least one movable section forming the part of such cam track which completes the discharge stroke of said pistons, and means for urging the cam surface of said movable section into contact with its related rollers so that the other rollers are urged into contact with the cam surface of the other cam track, said cam surfaces being spaced for restricting movement of the rollers from their engagement with their respective cam surfaces.

5. A filling machine, comprising: a reservoir adapted to contain liquid, metering mechanisms to receive liquid from said reservoir, each metering mechanism including a cylinder and a piston for metering liquid into said cylinder during travel on its intake stroke and for discharging liquid from said cylinder during travel on its discharge stroke, cam means for sequentially actuating said pistons on their intake and discharge strokes, said cam means including spaced apart horizontally and vertically olfset, parallel upper and lower cam tracks each having a cam surface, pairs of first and second rollers, single axis pin means for mounting one pair of said first and second rollers to each piston to eiiect engagement of said first rollers only with said cam surface of said upper can track and to effect engagement of said second roller: only with said lower cam surface, the cam surfaces of the upper and lower cam tracks being spaced a distance equai to the distance between the engagement of the first roller of the pair of rollers and the cam surface of the upper cam track and the engagement of the second roller oi the same pair and the lower cam surface to minimize movement of the pairs of rollers between the cam surfaces, a movable section forming part of one cam track for initiating the discharge strokes of said pistons and another movable section forming another part of said one cam track for completing the discharge strokes of said pistons, and means for urging said movable sections into engagement with not more than two of its related rollers.

References Cited UNITED STATES PATENTS 1,796,279 3/1931 Berg 141-147 2,141,618 12/1938 Roge 14l----147X 3,040,787 6/1962 Knoll 141147 X 3,097,672 7/1963 Minard 222168.5

ROBERT B. REEVES, Primary Examiner. 

